Yahweh uses a question to teach the people about the kind of fast that pleases him. Alternate translation: "This is the fast that I choose ... break every yoke." (See: [[rc://en/ta/man/translate/figs-rquestion]])
All of these phrases mean they should help those people whom the wicked are hurting and oppressing. (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-parallelism]])